Direct part marking is a process for permanently marking the surface of parts, such as surgical equipment, electronics components, and aerospace parts, with machine-readable symbols that contain encoded information. Many different types of marking methods can be used, for example, dot peen, electro-chemical etching, laser etching, and cast marks.
Examples of machine-readable symbols include linear barcodes, matrix barcodes, and text, and these machine-readable symbols are generally read with a scanner or imager having a point light source, such as a laser or light-emitting diode. The marked surface can be very shiny, and thus highly reflective. Consequently, when the point light source in the scanner illuminates the symbols on the specular surface, the image reflected back to the scanner is unreadable because it is too intense.